It is known from U.S. Pat. No. 4,142,051 of the same inventor that 1-cycloalkenoyl-2-phenyliminoimidazolidines, for example 1-(cyclohex-3-en-1-oyl)-2-(2,6-dichlorophenylimino)-imidazolidine, exhibit analgesic properties and can be used as active ingredients in pharmaceutical products for treating attacks of pain.
On the other hand, U.S. Pat. No. 3,988,345 of the same inventor, benclonidine (1-benzoyl-2-(2,6-dichlorophenylimino)-imidazolidine) and the three isomeric toluyl derivatives of clonidine are described as compounds which are primarily distinguished by a marked antihypertensive effect and which are suitable for the preparation of solutions for injection and, in particular, of medicaments for treating hypertension to be administered orally.
Finally 1-aroyl-2-phenyliminoimidazolidines are known from U.S. Pat. No. 4,389,403 in which the aroyl radical represents an optionally substituted monocyclic or bicyclic heteroaromatic acyl radical. These compounds are also said to have strong hypotensive effects.